Optimization of Grouting Reinforcement Mass Parameters for Shield Under-passing Buildings in Sandy Stratum
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 7
Abstract
Objective Grouting reinforcement is a common measure to reduce disturbance on existing buildings during tunnel construction. It is essential to focus on the design of GRM (grouting reinforcement mass) parameters in the engineering. Appropriate GRM parameters are crucial to ensure reinforcement effectiveness and reduce project costs. Therefore, it is necessary to optimize and analyze these parameters based on practical engineering conditions. Method Taking the tunneling project of Wuyi Overpass Station to Xinxiu Park Station interval on Nanning Rail Transit Line 5 as example, the under-passing construction is classified by the position relation between existing buildings and tunnel. Numerical calculations are used to optimize the GRM cross-sectional parameters, and the stress mechanism of the GRM is analyzed. On-site grouting reinforcement is carried out according to the parameter optimization results to validate the effectiveness of GRM parameter optimization. Result & Conclusion Under-passing construction is divided into three categories: under-passing directly beneath buildings, side-passing Type I buildings, and side-passing Type II buildings. For the first one, the GRM should extend into the micro-disturbance area by approximately 1 m, with a grouting thickness of 6 m. For the second and third, the GRM should extend approximately 4 m beyond the close tunnel side and penetrate 4 m into the micro-disturbance area on the far tunnel side, with a thickness of 6 m. The stress mechanism of the GRM can be simplified to anchor beams at both ends when under-passing directly beneath buildings and to cantilever beams when side-passing buildings. Monitoring results demonstrate that optimizing the GRM parameters can effectively control building deformation.
Authors and Affiliations
Xing HUANG, Chaofan YAO, Yang ZHOU, Gaoyu MA, Hao LIU, Chuan HE, Shimin WANG
Calculation Method of Crowd Density in the Local Area of Subway Station Platform
[Objective] The calculation method of crowd density is the key to analyzing the risk of crowd gathering on subway station platforms. Usually, the internal density distribution is uneven when it is crowded, and there ar...
Design of CBTC and ATP/TD Integrated On-board System
Objective In response to the continuously increasing passenger demands, Chongqing Rail Transit Line 2 requires signaling system upgrading and renovation for the previously launched Jiaochangkou-Xinshancun Interval. Based...
Analysis of Cracking Causes at Grounding Terminals of Bogie Axle-end and Resolution Measures
[Objective] Due to continuous changes in the operating conditions of metro lines, abnormal vibrations between wheel and rail s occasionally occur, leading to fractures in the suspension components at the bogie axle-end a...
Conversion Conditions for Fixed Temperature Difference with Variable Water Supply Temperature and Large Temperature Difference Control Strategies in Urban Rail Transit Station Air-conditioning Chilled Water System
Objective To achieve the lowest overall energy consumption of urban rail transit station air-conditioning chilled water system under both fixed temperature difference with variable water supply temperature and large temp...
Characteristics and Applicability Analysis of Flexible Scheduling for Urban Rail Transit Crews
[Objective] In view of the situation that the flexible crew scheduling method commonly used in foreign metro systems is barely applied in China, the applicability of flexible scheduling in Chinese metro system and the ma...